When was the Internet Born?

It was 40 years ago today, September 2, 1969 that scientists connected two computers at UCLA with a 15-foot cable and the machines were able to communicate with each other. The test data was meaningless, but the breakthrough eventually led to the formation of the internet, but there were plenty of other milestones. Which date is the birthday of the internet?

September 2, 1969: First time two computers communicated with each other.

Oct 29, 1969: Message sent from computer to computer in different locations.

1971: The first email was sent.

Jan 1, 1983: ARPANET adopted the standard TCP/IP protocol.

March 1989: Tim Berners-Lee invented the World Wide Web.

April 22, 1993: Mosaic became the first web browser.

Which date should we designate as the birthday of the internet? Link -via Buzzfeed